ML20066D630
| ML20066D630 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 01/09/1991 |
| From: | ENTERGY OPERATIONS, INC. |
| To: | |
| Shared Package | |
| ML20066D618 | List: |
| References | |
| NUDOCS 9101150242 | |
| Download: ML20066D630 (2) | |
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I TECHNICAL SPECIFICATION _ BASIS CHANGES I
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l 9101150242 910109 PDR ADOCK 05000368 P
3/4.8 ELECTRICAL POWER SYSTEMS BASIS The OPERABILITY of the A.C. and D.C, power sources and associated distribution systems during operation ensures that sufficient power will be available to supply the safety-related equipment required for 1) the safe shutdown of the facility and 2) the mitigation and control of accident conditions within the facility.
The minimum specified independent and redundant A.C. and D.C. power sources and distribution systems satisfy the requirements of General Design Criteria 17 of Appendix "A" to 10 CFR 50.
l The ACTION requirements specified for the levels of degradation of the power sources provide restriction upon continued facility operation commensurate with the icvel of degradation.
The OPERABILITY of the power sources are consistent with the initial condition assumptions of the accident analyses and are based upon maintaining at least one redundant set of onsite A.C. and D.C. power soutcos and associated distribution systems OPERABLE during accident conditions coincident with an assumed loss of offsite power and single failure of the other onsite A.C. source.
The OPERABILITY of the minimum specified A.C. and D.C. power sources and associated distribution systems during shutdown and refueling ensures that 1) the facility can be maintained in the shutdown or refueling condition for extended time periods and 2) sufficient instrumentation and control capability is available for monitoring and maintaining the unit status.
The Surveillance Requirements for demonstrating the OPERABILITY of the diesel generators are in accordance with the recommendations of Regulatory Guides 1.9 " Selection of Diesel Generator Set Capacity for Standby Power Supplies", March 10, 1971, and 1.108 " Periodic Testing of Diesel Generator Units Used as Onsite Electric Power Systems at Nuclear Power Plants",
Revision 1, August 1977.
With specific reference to Tech Spec 4.8.1.1.2.C.8,C, the term " diesel generator trips" is interpreted to mean " diesel generator protective trip" in the sense used in Regulatory Guide 1.108.
Engine start failure (overcrank) is not interpreted to be a " protective trip" since it serves only to preserve air for additional restart attempts when start failure is obvious and does not provide any " protective" feature for either the engine or generator.
Specifically the features which are interpreted as " diesel generator trips" which are to be bypassed on an SIAS start include generator phase overcurrent (with voltage restraint), generator loss of field and generator anti-motoring.
Containment electrical penetrations and penetration conductors are protected by either de-energizing circuits not required during reactor operation or by demonstrating the OPERABILITY of primary and backup overcurrent protection circuit breakers during periodic surveillance.
ARKANSAS - UNIT 2 B 3/4 8-1
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